Thomas a



( Model.)

T. A. EDISON. Electric Lamp.

Patented March 29,188I.

Winesses:

N4 PETERS PHOTO-LITHOGRAPHER WASHINGTON. D C.

UNITED STATES PATENT OFFICE.

THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.

ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 239,373, dated March29, 1881.

Application filed August 17, 1850. (Model) To all whom it may concern Beit known that I, THOMAS A. EDISON, of Menlo Park, in the county ofMiddlesex and State of New Jersey, have invented a new and usefulImprovement in Electric Lamps; and I do hereby declare that thefollowing is a full and exact description of the same, reference beinghad to the accompanying drawing, and to the letters of reference markedthereon.

This invention relates to a new method of manufacturing electric lamps,wherein an incandescing conductor is sealed in an exhaustedinclosing-globe; and it consists in the features more particularlyhereinafter described and claimed.

In patents hitherto granted me are shown lamps hermetically sealed by afusion of the glass at the union of the parts, making a permanent lampof great durability. Sometimes, however, it may be desirable to make alamp in which a less permanent seal is used, im'olving a less expensivemethod of sealing, and which may be taken apart readily for thesubstitution of a carbon or for other purposes. The drawing (one figure)illustrates such a lamp.

A is the inclosing-globe, made with a long neck, A, through which may bepassed the carbon B, attached to clamps b I), connected to conductors l2, which are sealed in the top of a tube, G, at c c, the tube 0 beingsomewhat smaller than the neck A. Around the base of C is a soft-rubberplug, D, which fits into the lower part of the neck A, forming a tightjoint between the two, supporting G and the 5 carbon in position in Aand A.

F is a socket or cup, through the bottom of which, by a tight joint,passes the end of O, the end of D resting in the cup. At the top of thecup a washer, E, of soft rubber, fills 4o tightly the space between Aand the inner wall of the cup F, the space in the cup being filled withmercury H or other suitable liquid.

The lamp so put together is exhausted and then sealed ata in the usualmanner, the com- 5 bination of the cup F, plugs or washers l) and E, andthe mercury H forming a reliable seal.

What I claim is- The combination, with the neck of the inclosing-globeand the carbonsupporting tube, 0

of a cup containing a liquid receiving the end of the neck of theinclosing-globe, and through which passes the carbonsupporting tube, andwashers or plugs filling the space between the neck and cup and the neckand tube, substan- 55

